The present invention relates to the field of digital computer systems, and more specifically, to a method for joining two data tables on a join attribute.
Databases of a system for massive parallel processing (MPP) may perform better if there is not much data to be exchanged in between nodes of the system. In case of joins in between tables, the optimal situation is if join keys are the same as distribution keys. However, if joining keys are not the same as distribution keys, then data have to be exchanged in between nodes leading to undesirable data performance.